Just double check if any .h or .cpp files landed in the Intermediate by accident. All c++ files should be in source.
Temp folders:
- .vs
- Binaries
- Intermediate
- DerivedDataCache
- Saved
Temp files:
.vsconfig
your .sln file
Regeneration should rebuild all of the above.
Edit: are you maybe adding #include "UDynamicMesh.h" under the .generated file?
.generated needs to be the last include for it to compile correctly
Tried your build config and it compiles ok even with the slashes
